Enhancement of perfume deposition from powder detergent into fabrics

Abstract: Scent is one of the most important factors affecting consumer satisfaction in the fast-moving consumer goods industry. However, the inherent volatile nature of perfume raw materials (PRMs) in formulated products as well as the impact of surfactants on their solubilization and spreading/retention on fabrics underpins the challenges associated with retention of perfume oils in woven substrates. Previous studies¹, including our own², show that surface spreading and penetration profile of emulsified oil droplets are determined by Weber number (We=ρD0v2/σ) and Reynolds number (Re=ρD0v/η)that incorporates interfacial tension (σ), density (ρ), droplet size (D₀), velocity (v), and share rate viscosity (η). By using optical tensiometry, we studied the ability of different surfactants to control liquid-liquid interfacial tension (σ) of PRMs at concentrations of interest, optimising the combinations of PRMs and surfactants. The other parameter that can be controlled by formulation is the emulsion droplet size (D₀), which was investigated by coupling a microfluidic setup with a fluorescence microscope. This method is able to determine droplet size, and to track the penetration kinetics of droplets through various fabric substrates of interest. We show that the physical characteristics of PRMs, such as interfacial tension and droplet size, could be modulated quantitatively at lab scale, for improved fabric retention.

1. De Goede, et al. Phys. Fluids 33, 033308 (2021).
2. Argentou, et al. RSC Adv., 2022, 12, 2160.